These symptoms may appear and then go away as the malformation bleeds and then reabsorbs blood.

What causes cavernous malformations?

The exact cause of cavernous malformations is not well understood, though some types may be inherited. If many family members have seizure disorders or blood vessel abnormalities on the skin, other family members may be at higher risk for a cavernous malformation.

The malformation results when small blood vessels (capillaries) within the brain group into enlarged or irregular masses. Compared to other blood vessels, capillaries have thin walls. So when they stretch out from excessive blood flow, they often cannot return to their normal size.

Head trauma may increase the risk for cavernous malformations to bleed, so doctors recommend that children with cavernous malformations avoid activities and sports with a high likelihood of head trauma, such as football.

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